The present invention relates to video delivery, recording and monitoring systems, and more particularly to a LAN/WAN based system where both the user and administrator interface need not be local to the system but can be on any remote node either attached to the main system via a Local Area Network (LAN) or Wide Area Network (WAN).
Since the early 70s various analog electronic video systems have been available for viewing and recording video. These systems are described as Closed Circuit TV (CCTV) systems. CCTV systems support cameras designed to transmit standard television input signals designed by the National Television System Committee (NTSC) in 19531. A CCTV system supports multiple NTSC cameras connected to NTSC multiplexer which in turn connected to a video display and possibly a time lapse recorder (the video in this description never leaves the analog domain). This system is a closed loop system where video does not migrate outside the site where the system resides. Such multiplexing devices include: Panasonic WJFS409, Sony YS-DX516. 1 NTSCNTSC stands for National Television System Committee, which devised the NTSC television broadcast system in 1953. NTSC is also commonly used to refer to one type of television signal that can be recorded on various tape formats such as VHS, ¾″ U-matic and Betacam.The NTSC standard has a fixed vertical resolution of 525 horizontal lines stacked on top of each other, with varying amounts of “lines” making up the horizontal resolution, depending on the electronics and formats involved. There are 59.94 fields displayed per second. A field is a set of even lines, or odd lines. The odd and even fields are displayed sequentially, thus interlacing the full frame. One full frame, therefore, is made of two interlaced fields, and is displayed about every 1/30 of a second.
Recently in the late 90s, a trend has started to replace the time lapse recorder with a digital video recorder (DVR). The DVR converts NTSC output from the video multiplexer to packets of digitized video and stores the now digitized video in files on a hard drive. More recently, DVR began to combine the functionality of the DVR and multiplexer into a single unit. Such devices include: Pelco DX-9000, DVMRc4CT40 GE/Kalatel, Sony HSRX216/32.
An example of a DVR configuration is shown in FIG. 3. This example shows a monitor plugged into a DVR. The DVR also connects to the multiplexer, which takes analog video feeds from all the cameras. By timesharing analog video streams, the DVR converts each video stream internally to digital and then saves the video on a hard drive that may be internal to the DVR itself.
In the past several years a few systems have emerged where the system no longer requires traditional analog cameras transmitting NTSC video signals. These systems connect to a network of digital IP cameras, (typically using TCP/IP). The DVR is replaced with a network video recorder (NVR, FIG. 1 item 3) which receives digitized video packets directly from cameras or devices known as video servers. Such cameras UP include: DLINK DCS-1000W, AXIS 2100, and VivoTek 3133 (FIG. 1 items 1/2).
FIG. 4 shows a variety of network camera configurations that support the digital or IP video model described above. The first example is a digital IP camera physically connected to the network. The second example shows an analog camera connected to a video server (that converts analog video to digital video) and thus can deliver IP video across the network. Example 3 is a digital IP camera with a built in wireless transmitter. The transmitter talks to a device such as a wireless access point that then physically connects to the network. Example 4 shows a wireless Ethernet bridge connecting to a, normally wired Ethernet (or IP camera). Example 5 shows the same configuration as 3 but the video server is now a wireless video server that talks to a wireless receiver such as an access point. Example 6 is the combination of a wireless Ethernet bridge connected to a device as described in item 2 (wired Ethernet video server).
This form of a video management system has made it possible for video information to be processed as is any form of digital data and made available to any network connected system or user. Networked video system becomes an immediate beneficiary of other stand-alone networking peripherals that exist in the market place. Such peripherals include: network hard drives, network servers, and other forms of network mass storage systems.
In general once video data is digitized it can be referenced in its raw data form from any “connected” system. The migration from single-ended video systems into fully networked solutions introduces many new complexities to a once simply managed closed-loop system. Along with the complexities are enormous new possibilities for management, processing and usage of the now digitized data
What is desired is to handle the situation where a remote networked device (IP camera/IP video server) locks up or hangs and cannot be restarted from the remote device server or any other such remote mechanism.